interstate ##s . it was also included in the general location of national system of interstate highways including all additional routes at urban areas designated in september 1955 , or yellow book after the cover color , that was released in 1955 as the federal government read ##ied plans for the freeway system . the proposed number in 1958 was interstate 75 ( i ‑ 75 ) . the first section of freeway was built in late 1957 or early 1958 between evergreen shores and m ‑ 123 north of st . ign ##ace . the mack ##ina ##c bridge was opened to traffic on november 1 , 1957 ; a new section of freeway and an interchange connected us 2 to the bridge . in 1961 ,
interstates. it was also included in the general location of national system of interstate highways including all additional routes at urban areas designated in september 1955, or yellow book after the cover color, that was released in 1955 as the federal government readied plans for the freeway system. the proposed number in 1958 was interstate 75 ( i ‑ 75 ). the first section of freeway was built in late 1957 or early 1958 between evergreen shores and m ‑ 123 north of st. ignace. the mackinac bridge was opened to traffic on november 1, 1957 ; a new section of freeway and an interchange connected us 2 to the bridge. in 1961,